中国物理B ›› 2023, Vol. 32 ›› Issue (1): 18509-018509.doi: 10.1088/1674-1056/ac9b35

所属专题: SPECIAL TOPIC — Physics in micro-LED and quantum dots devices

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A polarization mismatched p-GaN/p-Al0.25Ga0.75N/p-GaN structure to improve the hole injection for GaN based micro-LED with secondary etched mesa

Yidan Zhang(张一丹)1,2, Chunshuang Chu(楚春双)1,3,†, Sheng Hang(杭升)1,2, Yonghui Zhang(张勇辉)1,2, Quan Zheng(郑权)4, Qing Li(李青)4, Wengang Bi(毕文刚)2, and Zihui Zhang(张紫辉)1,2,‡   

  1. 1 State Key Laboratory of Reliability and Intelligence of Electrical Equipment, Hebei University of Technology, Tianjin 300401, China;
    2 School of Electronics and Information Engineering, Hebei University of Technology, Key Laboratory of Electronic Materials and Devices of Tianjin, Tianjin 300401, China;
    3 School of Electrical Engineering, Hebei University of Technology, Tianjin 300401, China.;
    4 State Key Engineering Center of Flat-Panel-Display Glass and Equipment, Shijiazhuang 050035, China
  • 收稿日期:2022-07-28 修回日期:2022-09-20 接受日期:2022-10-19 出版日期:2022-12-08 发布日期:2023-01-14
  • 通讯作者: Chunshuang Chu, Zihui Zhang E-mail:cs.chu@hebut.edu.cn;zh.zhang@hebut.edu.cn
  • 基金资助:
    This work was supported in part by the National Natural Science Foundation of China (Grant Nos. 62074050 and 61975051); Research Fund by State Key Laboratory of Reliability and Intelligence of Electrical Equipment, Hebei University of Technology (Grant Nos. EERI PI2020008 and EERIPD2021012); and Joint Research Project for Tunghsu Group and Hebei University of Technology (Grant No. HI1909).

A polarization mismatched p-GaN/p-Al0.25Ga0.75N/p-GaN structure to improve the hole injection for GaN based micro-LED with secondary etched mesa

Yidan Zhang(张一丹)1,2, Chunshuang Chu(楚春双)1,3,†, Sheng Hang(杭升)1,2, Yonghui Zhang(张勇辉)1,2, Quan Zheng(郑权)4, Qing Li(李青)4, Wengang Bi(毕文刚)2, and Zihui Zhang(张紫辉)1,2,‡   

  1. 1 State Key Laboratory of Reliability and Intelligence of Electrical Equipment, Hebei University of Technology, Tianjin 300401, China;
    2 School of Electronics and Information Engineering, Hebei University of Technology, Key Laboratory of Electronic Materials and Devices of Tianjin, Tianjin 300401, China;
    3 School of Electrical Engineering, Hebei University of Technology, Tianjin 300401, China.;
    4 State Key Engineering Center of Flat-Panel-Display Glass and Equipment, Shijiazhuang 050035, China
  • Received:2022-07-28 Revised:2022-09-20 Accepted:2022-10-19 Online:2022-12-08 Published:2023-01-14
  • Contact: Chunshuang Chu, Zihui Zhang E-mail:cs.chu@hebut.edu.cn;zh.zhang@hebut.edu.cn
  • Supported by:
    This work was supported in part by the National Natural Science Foundation of China (Grant Nos. 62074050 and 61975051); Research Fund by State Key Laboratory of Reliability and Intelligence of Electrical Equipment, Hebei University of Technology (Grant Nos. EERI PI2020008 and EERIPD2021012); and Joint Research Project for Tunghsu Group and Hebei University of Technology (Grant No. HI1909).

摘要: A low hole injection efficiency for InGaN/GaN micro-light-emitting diodes (μLEDs) has become one of the main bottlenecks affecting the improvement of the external quantum efficiency (EQE) and the optical power. In this work, we propose and fabricate a polarization mismatched p-GaN/p-Al$_{0.25}$Ga$_{0.75}$N/p-GaN structure for 445 nm GaN-based μLEDs with the size of $40 \times 40 $μm$^{2}$, which serves as the hole injection layer. The polarization-induced electric field in the p-GaN/p-Al$_{0.25}$Ga$_{0.75}$N/p-GaN structure provides holes with more energy and can facilitate the non-equilibrium holes to transport into the active region for radiative recombination. Meanwhile, a secondary etched mesa for μLEDs is also designed, which can effectively keep the holes apart from the defected region of the mesa sidewalls, and the surface nonradiative recombination can be suppressed. Therefore, the proposed μLED with the secondary etched mesa and the p-GaN/p-Al$_{0.25}$Ga$_{0.75}$N/p-GaN structure has the enhanced EQE and the improved optical power density when compared with the μLED without such designs.

关键词: μLED, polarization mismatch, secondary etched mesa, hole injection

Abstract: A low hole injection efficiency for InGaN/GaN micro-light-emitting diodes (μLEDs) has become one of the main bottlenecks affecting the improvement of the external quantum efficiency (EQE) and the optical power. In this work, we propose and fabricate a polarization mismatched p-GaN/p-Al$_{0.25}$Ga$_{0.75}$N/p-GaN structure for 445 nm GaN-based μLEDs with the size of $40 \times 40 $μm$^{2}$, which serves as the hole injection layer. The polarization-induced electric field in the p-GaN/p-Al$_{0.25}$Ga$_{0.75}$N/p-GaN structure provides holes with more energy and can facilitate the non-equilibrium holes to transport into the active region for radiative recombination. Meanwhile, a secondary etched mesa for μLEDs is also designed, which can effectively keep the holes apart from the defected region of the mesa sidewalls, and the surface nonradiative recombination can be suppressed. Therefore, the proposed μLED with the secondary etched mesa and the p-GaN/p-Al$_{0.25}$Ga$_{0.75}$N/p-GaN structure has the enhanced EQE and the improved optical power density when compared with the μLED without such designs.

Key words: μLED, polarization mismatch, secondary etched mesa, hole injection

中图分类号:  (Semiconductor-device characterization, design, and modeling)

  • 85.30.De
85.35.Be (Quantum well devices (quantum dots, quantum wires, etc.)) 85.60.Bt (Optoelectronic device characterization, design, and modeling) 85.60.Jb (Light-emitting devices)